Improvement in spirit-level



@ate-ut Gemine.-

`nnwnvll. s'rnArToN AND cnantnsn. Vszlna'rroN, or. cnnnnrn'lnn;

MASSACHUSETTS.

l l Letteo's'Patent'No(100,463,0dated M'lrch- 1, 1870. 'v

IMPRovEMENT '1N SPIRIT-LEVEL.

The Schedulereferredt'o in'these Letters Patent and making part of the seme.

j Toall whom it may concern: l

Be it knownthat we, EDWIN A. STnA'r'rox and CHARLES M.` STRATTON, both et Greenfield, in the county of Franklin, and State'of Massachusetts, have invented a new andusefnl Improvement vin Spirit- -Levcls; and we do hereby declare the following, when taken in connection with the accompanying drawings ,j i and the` 1ct-ters of referencemarked thereon,ito be a full, clear, and exact description thereof', and which said dra-wings constitute part of this specification, and representin'- i `Figure l a side view of a spirit-level with our invention applied. l i

Figure 2 represents a plan view of the same, and Figure 3 ,is a transversesection, through line B G ofiig.2. Our invention relates to that class of spirit-levels wherein the stock or; bar is 'made of wood; and

It consists of a` metallic rodrhaving longitudinal projections ther'eon, and so constructed that, ifonc corner of the stock be cut away longitudinally, ofthe same form in crossfsectionas the form. ofthe metallic rod in its cross-scction,lthe said rod maybe forced into the space-so mad@ fronione end, and the longitudinal projections upon said rod will retain it securely in its place, said rod, when there is one placed'at each `corner of the bar orstock of the spirit-level,` serving tol protect the corners of the wood from abrasion and injury, and assisting in preserving the stockVso that it may remain' -true and perfect in the operation of the That others skilled inv thcart may be able to make and use the same, we' will proceed to describe its coustruction and its application to use.

In the .drawings-4 l p' i A` represents the stock in whichthe.bubble-glass is placed, which stockl may be'piismatie in form in its cross-section, the usual form adopted, or it may be of any otberdesirable form. t

The small portion of wood at each corner yof the' stock may he removed longitudinally, in the'iollowing manner: l

A small ci1'culai'-saw maybe arranged so thatwits teeth may project above its4 ltable or platform just enough to `enter the wood `to make one of the grooves i. If the guide usually attached to the table be adjusted rightly, `the stock A may be placed upon the `table upon its side l), and the saw heilig put in mo-' tion, if the stock bepassed along the table `over the saw, one of the grooves is made.` The' stock is then placed upon the other side 1*],and the other groove i in the same corner is made,`which operation removes the wood along that cornerof the stock.

A metallic rod, of a size in its cross-section to lill this space occasioned by the removal of the wood,' aud with longitudinal projections thereon to till the grooves .1', is placed in said space by inserting the end of the. p

rod in the end of thc space or groove, and forcing it in e-ndwise or longitudinally.. maybe finished off square with the end of thc stock, and a metallic piece, (t, may be secured to thcend of the stock, covering the ends of the metallic rods e to make a better finish and prevent the rods from coming out-. rlhe metallic rods c may be drawn by the' saule opera-tion as in drawing wire, or they may be. cast or made by auyother convenient and desirable process.l XVe prefer the process ot' drawing them.

This invention, it is' evident, may be applied to spirit-levels of any form and size, the stocksof which are made of wood or of any material other' .than metal which can be operated upon easily, andthe form p v of the grooves i or of the rods c in their cross-section may befvaried without in the least departing from the prncipleof its operation.` y

The longitudinal projections which Vfit the grooves 'i might be sutiiciently 'strong andV equally operative. if they occurredat intervals along the rod, and a saving `of stock be made thereby ;l but such construction would be merely an equivalent to that herein shown,

while the difficulty of manufacture would be increased unless the rods w-ere cast. f

We are aware that metallic pieces have heretofore beeuscrcwcd to the `angles of spirit-levels having a wooden stock; and we are also aware that a system of grooves and' tenons has heretofore been used inthe construction of wooden boxes, and we do not claim' Athe same or citlier of them separately considered; but

Havingdcscribed our invention, Y

What we claim as new, and desire to secure by Lctters Patent, is

As a new article of manufacture, an improved spiritlevel, having the cornersfof tlid wooden stock A protected by the metallic rods e, attached and secured in place, substantially as and for the purposes speciiied.

, EDWIN A. STItATlfON.

(JHARLES M. ST i-AT'JON.

Witnesses 'WENDELL T. Devis, At's'rrs DnWoLF.

"he ends of thc rods 

